Iodine-doped multiwall carbon nanotubes (I-MWNTs) were characterized by means of Raman scattering and thermogravimetric analysis. The results show that multiwall carbon nanotubes (MWNTs) can be effectively doped by iodine and exchange electrons with iodine. Iodine atoms form charged polyiodide chains inside tubes of different inner diameter, which is similar to the iodine-doped single-wall carbon nanotubes (I-SWNTs), but can not intercalate into the graphene walls of MWNTs. The Raman scattering behavior of I-MWNTs exhibits some differences from that of I-SWNTs and the low-dimensional conductive hydrocarbon-iodine complex “perylene⋅I2.92.”

Large-scale SiO2 nanowires were synthesized by using a simple but an effective approach at low temperature. Scanning electron microscopy, transmission electron microscopy, and x-ray photoelectron spectroscopy were employed to characterize the samples. The results indicated that SiO2 nanowires with a uniform diameter of about 20 nm and a length up to 10 μm have been synthesized. Photoluminescence measurement showed that the SiO2 nanowires emitted blue light at 2.8 and 3.0 eV. The possible growth process of the SiO2 nanowires is discussed. Using this method, large panels of SiO2 nanowires can be made under conditions that are suitable for device fabrication.

The p-n tandem design of a sensitized solar cell is a novel concept holding the potential to overcome the efficiency limitation of conventional single-junction sensitized solar cells. Significant improvement of the photocurrent density (Jsc) of the p-type half-cell is a prerequisite for the realization of a highly efficient p-n tandem cell in the future. This study has demonstrated effective photocathodes based on novel organometal halide perovskite-sensitized mesoporous NiO in liquid-electrolyte-based p-type solar cells. An acceptably high Jsc up to 9.47 mA cm(-2) and efficiency up to 0.71% have been achieved on the basis of the CH3NH3PbI3/NiO solar cell at 100 mW cm(-2) light intensity, which are significantly higher than those of any previously reported liquid-electrolyte-based p-type solar cells based on sensitizers of organic dyes or inorganic quantum dots. The dense blocking layer made by spray pyrolysis of nickel acetylacetonate holds the key to determining the current flow direction of the solar cells. High hole injection efficiency at the perovskite/NiO interface and high hole collection efficiency through the mesoporous NiO network have been proved by time-resolved photoluminescence and transient photocurrent/photovoltage decay measurements. The limitation of these p-type solar cells primarily rests with the adverse light absorption by the NiO mesoporous film; the secondary limitation arises from the highly viscous ethyl acetate-based electrolyte, which is helpful for the solar cell stability but hinders fluent diffusion into the pore channels, giving rise to a nonlinear dependence of Jsc on the light intensity.

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This study aimed to examine gender differences in the association between serum uric acid (SUA) and the risk of prediabetes in a longitudinal cohort. A total of 8237 participants in the Beijing Health Management Cohort study were recruited and surveyed during 2008–2009, and followed up in 2011–2012 and 2014–2015 surveys. Generalized estimating equation (GEE) models were used to evaluate the association between SUA and prediabetes. Furthermore, subgroup analyses assessed the primary outcome according to status of abdominal obesity, age and status of hypertension. During six years of follow-up, we identified 1083 prediabetes events. The GEE analyses confirmed and clarified the association between SUA and prediabetes (RR = 1.362; 95% CI = 1.095–1.696; p = 0.006) after adjusting for other potential confounders, especially in females (RR = 2.109; 95% CI = 1.329–3.347; p = 0.002). In addition, this association was stronger in the subgroup of females aged ≥48 years old (RR = 2.384; 95% CI = 1.417–4.010; p = 0.001). The risk for prediabetes increased significantly with increasing SUA for females in the Chinese population. This association was strongly confirmed in older females aged ≥48 years old rather than in younger females, which may provide clues for pathogenic mechanisms of gender differences in the association between SUA and prediabetes.